1. Field of the Invention
The present invention generally relates to a linkage apparatus or binding for attaching a boot to a ski, and particularly to a binding for attaching a boot to a cross-country ski. More particularly, the present invention relates to an apparatus which includes a support which is adapted to be pivotably mounted about a first axis which is transverse with respect to the longitudinal extent of the ski, which support has a rear portion with a retention apparatus for the front end of a boot. The apparatus also includes means for elastically biasing the support rotatably about the axis with respect to the ski, so that the support will move rearwardly and downwardly with respect to the ski to clamp the boot on the ski.
2. Description of Background Art and Relevant Information
Throughout the specification the terms top, bottom, front and rear are used with respect to the normal use of a cross-country ski, which is generally used in a flat position and which is supported on a generally horizontal support surface. These terms are also used with respect to the normal displacement of the ski.
Binding apparatus for cross-country skis are known, e.g., in commonly assigned French Application No. 2,447,731 (particularly with respect to its FIGS. 29 and 30) as well as in French Patent Application Serial No. 2,537,011, which is also commonly assigned (the latter French patent is specifically relevant with respect to its FIGS. 8 and 9).
Known apparatus are adapted to be mounted on a ski having a smooth longitudinal upper surface, and on which a flat base plate is screwed so as to define a transverse axis of rotation for a support with respect to the ski.
Cross-country skis are presently being developed with an upper surface having a longitudinal rib bordered by two longitudinal upper surface strips located on either side of the central rib. The strips are connected to the upper surface of the center rib by two upwardly extending generally vertical surfaces, which surfaces can be inclined if desired.
In such ribbed skis, the apparatuses described in the above two noted French patents can be mounted via a compensating element which is adapted to cover the rib and the longitudinal upper surface strips of the ski which are located on each side of the rib. The compensation element includes a smooth upper surface which is adapted to permit mounting of the base plate on a conventional ski. Similarly, the base plate can be configured along the bottom such that it will mate with the ski rib as well as the longitudinal upper surface strips which border the central rib. In both cases, it is appropriate to modify the shape and configuration of the apparatus for retaining the front end of a ski boot on the support so as to take into account the variety of possible positions of a boot on the ski.
Adapting such present apparatus is not entirely satisfactory, insofar as it causes the binding apparatus to rise with respect to the ski, particularly with respect to the longitudinal edges of the ski, thereby increasing friction of the ski against the snow as well as increasing the risks of accumulating snow in front of the apparatus. Further, such apparatus is vulnerable and susceptible to shocks, particularly along its front portion where the elastically biasing means are positioned, thereby increasing the risk of deterioration of the biasing member and the entire ski and binding.
Accordingly, one general aim of the present invention is to overcome the above-noted disadvantages by providing an apparatus for attaching the front end of a shoe or boot to a ski, and more particularly to a cross-country ski. The attachment apparatus is specifically adapted for use with a ski having an upper surface with a longitudinal rib bordered by two longitudinal upper surface strips.